1. Field of the Invention
This invention relates generally to tensioning devices and, more particularly, to a tensioning device or autotensioner of the self-contained type in which fluid is sealed within the assembly with no provision for its replacement from any external source during operation for a tensioned belt, chain or the like.
2. Discussion of the Background
In conventional self-contained tensioning devices, such as shown in Japanese Utility Model Laid-Open Application No. 57(1982)-155350, the operating fluid is sealed within the assembly and is prevented from flowing out toward the exterior by a sealing member. However, when the operating fluid flows out due to damage of the sealing member, the self-contained tensioning device cannot maintain a pressing force for tensioning the belt or similar structure and, as a result, the belt is allowed to sag.